KUIPER AIRBORNE OBSERVATORY
About the Kuiper Airborne Observatory
During taxi, takeoff, and ascent, aircraft vibrations are transmitted with
little damping throughout the telescope structure. About five to ten minutes
before observing is to begin, the Telescope Operator at the Main Console begins
activating the telescope stabilization system. First, the four vibration
isolators are activated. The telescope is then "up on isolators" and partly
insulated from aircraft vibration. After airflow around the air-bearing is
started, the telescope may be "uncaged". Linear uncaging allows the telescope to
be "floating" on the air-bearing. Rotary uncaging permits slewing of the
telescope to the desired elevation angle. Unless balance is being checked, the
telescope will be gyro-stabilized when it is floating. The telescope must be
caged before the aircraft turns onto a new heading.
The Gerard P. Kuiper Airborne Observatory (KAO) is a national facility operated
by the National Aeronautics and Space Administration to support research in
infrared astronomy. The observation platform is a highly modified C-141A jet
transport aircraft with a range of 6000 nautical miles, capable of conducting
research operations to 45000 feet (14 km).
The KAO's telescope is a conventional Cassegrain reflector with a 36-inch (91.5
cm) aperture, designed primarily for observations in the 1 to 500 micron
spectral range. The telescope looks out the left side of the aircraft at an
elevation of between 35 and 75 degrees.
The KAO is based at the Ames Research Center (aerial view - 583 KB) at Moffett Field, California (near
San Jose, CA). It is operated as a facility for scientists whose proposals have
been deemed suitable and have been approved by NASA. Those scientists perform
research with scientific instruments which have often been developed especially
for use on the aircraft. Each instrument may be installed on the aircraft for a
few days to several weeks, allowing multiple flights and investigators using the
The KAO performs astronomical observations analogous to those made in
ground-based or space-based telescopes. The KAO's observing capabilities fill a
unique niche in astronomical science, however. Its flight capability allows it
to rise above much of the water vapor in the earth's atmosphere (allowing
observations of infrared radiation which is blocked before reaching ground-based
facilities), as well as travel to almost any point on the earth's surface for an
observation. At the same time, in between flights the facility is ground-based,
allowing systems development, maintenance, and repair.
To perform astronomy while in flight, a number of systems must work together to
provide a stable observation platform. Several sub-systems or steps are involved
in this process. They include:
Each of these is described in further detail, and the use of the systems as a unit provides
a lesson on KAO Telescope Operations.
- - the aircraft autopilot
- - the vibration isolation system
- - the spherical air bearing
- - the gyro-stabilization system
- - the video star tracker
The telescope aperture door is normally kept closed until the aircraft is at
35,000 feet or higher. After the flight crew have leveled off the aircraft at
the initial assigned altitude, the door is raised to expose the telescope.
Opening the door takes about two minutes. After the Mission Director receives
verification from the flight deck that the aircraft will remain level and is on
the correct heading, the Telescope Operator may uncage the telescope and
transfer control from the Main Console to the forward joystick and Tracker
Console. The Tracker Operator or the Investigator will then have control of the
telescope for fine pointing.
The aircraft began as a Lockheed Model L300 Starlifter jet transport, originally
configured as a prototype commercial version of the U.S. Air Force C-141A. The
telescope system was designed and built by the Fecker Systems Division of the
Owens-Illinois Corporation. The telescope cavity was designed and installed by
Lockheed Aircraft Services in May 1973. Research operations began in February,
1974, and the facility was dedicated as the Gerard P. Kuiper Airborne
Observatory (KAO) in May, 1975.
The information on this page was taken from the Kuiper home pages by Florentino.
Here is information about the original KAO WWW Authors
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